Global Warming off the hook? Alien species are primary cause of recent global extinctions

Alien species are primary cause of recent global extinctions

Alien species are the main driver of recent extinctions in both animals and plants, according to a new study by UCL researchers.

University College London

Alien species are the main driver of recent extinctions in both animals and plants, according to a new study by UCL researchers. They found that since 1500, alien species have been solely responsible for 126 extinctions, 13 percent of the total number studied. Credit P Krillow

Alien species are the main driver of recent extinctions in both animals and plants, according to a new study by UCL researchers.

They found that since 1500, alien species have been solely responsible for 126 extinctions, 13% of the total number studied.

Of 953 global extinctions, 300 happened in some part because of alien species, and of those 300, 42% had alien species alone listed as the cause of their demise.

The study, published today in Frontiers in Ecology and the Environment, used data from the 2017 IUCN Red List on the total numbers of species that are considered to have gone extinct globally since 1500.

In total, 261 out of 782 animal species (33.4%) and 39 out of 153 plant species (25.5%) listed aliens as one of their extinction drivers. In contrast, native species impacts were associated with only 2.7% of animal extinctions and 4.6% of plant extinctions.

“Some people have suggested that aliens are no more likely than native species to cause species to disappear in the current global extinction crisis, but our analysis shows that aliens are much more of a problem in this regard,” said lead researcher Professor Tim Blackburn (UCL Biosciences).

“Our study provides a new line of evidence showing that the biogeographical origin of a species matters for its impacts. The invasion of an alien species is often enough to cause native species to go extinct, whereas we found no evidence for native species being the sole driver of extinction of other natives in any case.”

The IUCN Red List identifies 12 broad categories of extinction drivers, including alien species, native species, biological resource use (hunting and harvesting) and agriculture. Alien species ranked first as a driver of animal extinctions, well ahead of the second place driver, biological resource use, which affected 18.8% of those lost.

Overall, the number of animal extinctions caused in some part by alien species is more than 12 times greater than those caused in part by native species.

Some of the worst offenders are mammalian predators, such as black, brown and Pacific rats and feral cats, with island habitats hit the hardest. Some of these animals first invaded by stowing away on boats, though some, like cats and foxes, have been introduced deliberately.

Many plants were also intentionally introduced, such as plantation tree species or ornamental plants for gardens. Once in place, they start to spread and threaten the native flora and fauna around them; alien plants are several times more likely than natives to achieve a maximum cover of at least 80%.

The origin of some species is unknown, so Professor Blackburn and his team assumed these were native for the study. “However,” he said, “it is more likely that they are alien. Our results are therefore conservative in terms of the extent to which we implicate alien species in extinction. Also, many regions of the world have not been well studied, and there are likely to be further extinctions that haven’t been captured in these data.”

The research team believes better biosecurity is needed to prevent future invasions, and in many cases measures to control or even eradicate alien species must be considered.

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Notes to editor

Tim M Blackburn, Céline Bellard and Anthony Ricciardi, ‘Alien versus native species as drivers of recent extinctions’ will be published in Frontiers in Ecology and the Environment on Monday 4 March 2019, 00.01 UK time and is under a strict embargo until this time.

Don’t forget to include homo sapiens as a possible invading “alien” species. Man arrives in the Americas in large numbers, and large numbers of native megafauna become extinct. Same for Australia, the Moas in New Zealand, and so on. Perhaps some of this is coincidence, and you’ll always get an argument against this idea because it makes many people uncomfortable, but in paleontology the timeline is what it is.

Here in Australia, one of the main causes of extinctions is that they were natural, predictable and part on the grand scheme of nature.
You cannot place a species in a new habitat without some expectation that it will evolve into a new species (for the purposes of classification) and face a much higher risk of extinctions than the parents at home.

The topic would be incomplete if there is no measure of the normal extinctions rate, the one that has happened before global warming was invoked. It is misleading math to take a former natural rate and now blame global warming for it. Geoff

Just to be argumentative, I posit that the Bramble Cay Melomys is an entirely natural and predictable extinction, assuming this mouse is actually extinct and was genetically distinct enough to be considered a distinct species. Any species living on a small and low-lying island in an area with period cyclones is just asking to be part of the grand scheme of nature.

Many were on very confined areas like tiny islands; many were so like their forebars that they mght or might not be species depending on disequilibrium between the lumpers and the splitters; some, as I wrote in the 1970s about the orange bellied parrot, were destined for extinctions because they were so stupid as to try to live in the barren wet desert of south-western Tasmania. That is what I meant by blogging that they were destined for extinction as part of natural evolution.
Geoff

It does seem to be another case of research being misrepresented, the link to the article does not work, so I don’t know who is responsible for the misrepresentation. “Alien species are the main driver of recent extinctions in both animals and plants” is incorrect as it clearly states the finding that “Of 953 global extinctions, 300 happened in some part because of alien species.” Since when has less that a third been “main”?

The silly things in the research is that they felt in necessary to prove the obvious, and the claim of a “global extinction crisis.”

Although evolution is often described as “survival of the fittest” it is better described as “non-survival of the less fit.” Occasionally the fitter species will evolve locally, but more often it moves in from outside.

Correction, it is the link to the paper that does not work, the article in EurekAlert can be accessed and does contain the incorrect claim “Alien species are the main driver of recent extinctions in both animals and plants.” So it is either EurekAlert or University College London that is making the incorrect claim.

However, no mention of climate change, so the headline is the responsibility of charles the moderator; at least he did put a question mark after “Global Warming off the hook” something that not supported by the article.

Bill,
IF invasive species are responsible for the greatest SINGLE cause (28%) and all other single causes are lesser in their affect on indigenous species (#2 was 18%), couldn’t it honistly be claimed that Invasive Species are the single largest set (AKA Main Driver)?

“ “Alien species are the main driver of recent extinctions in both animals and plants” is incorrect as it clearly states the finding that “Of 953 global extinctions, 300 happened in some part because of alien species.” Since when has less that a third been “main”?”

BillP, don’t be hasty at being critical. Reading comprehension can be your friend.

The author DID NOT stipulate that ALL “953 global extinctions” …… were ALL “recent extinctions”, …… now did he?

For all you or I know, there may have only been 400 of the 953 extinctions that were categorized as being “recent”, therefore, iffen 300 of the 400 was due to “alien species”, ….. then alien species was the main driver.

What are the chances of one correctly determining the actual cause of an “extinction event” that occurred 50+ or 100+ years ago? They are not all as simple to solve as is/was the Passenger Pigeon extinction. And no one actually knows for sure that the Ivory Billed Woodpecker is extinct, ….. or “why”, ……. iffen it is extinct.

Bryan A: I cannot seeing any evidence to suggest that, the abstract certainty does not claim that. All sorts of things could be true, but the issue is what does the paper show?

tty: No; but we are discussing a specific paper that does not explain the majority of extinctions. So that is one of the all sorts of things that could be true.

Samuel C Cogar: Unless one of us pays to access the actual paper we cannot be sure about the details. However it is clear that it does not show that alien species are the main cause of extinctions, just that alien species cause many more than native ones.

“However it is clear that it does not show that alien species are the main cause of extinctions, just that alien species cause many more than native ones.”

SURPRISE, SURPRISE, ….. BillP, …… I could have told you that, ….. that “alien species cause many more extinctions than native species”, ……. and I wouldn’t have had to spend 1/2 million dollars and a couple years doing a study just to figure it out.

“DUH”, ……. BillP, … at one time or another, … during past times, … every one of the current resident species was itself an invasive foreign species that encroached upon a speciesless “turf” ….. or the “turf” of a resident species …… and they “duked” it out for control of said “turf” and most are now living in a pseudo-symbiotic relationship.

And as the climate “warms and cools”, …… species will migrate to the “turf” that supports them, even if they have to “fight” for it.

Jon Peterson, since no one actually knows for sure, ……. who built the Sphinx & Great Pyramid of Gisa in Egypt, the stonework at Puma Punku, Bolivia or the stonework at Gobekli Tepe in Turkey, …… one might as well claim that “aliens constructed them all”.😊 😊

What the [SNIP] was that? we all know how the review system is buggered and the people handing out grants are barking mad…..but is there no oversight of all this bizarre crap at all?
If not, give me the job of fixing it, because I will fix the [SNIP] out of it.
I don’t want to sound too enraged, I laughed at it, but it felt like the laugh of the damned.

just a sidebar obsveration: As a lot, read most, of today’s Leftists seem to be advocates of the Government backed CAGW theory and wishing for, read advocating demonstrably for, the Government to take action, read power over the people, to combat it; those same leftists will read this article with consternation regarding aliens species invading foreign habitats. Wouldn’t it be a refreshing change if they developed the same consternation for aliens citizens invading the habitats of foreign countries. Here in the Good old USofA that alien invasion doesn’t seem to bother them.

Around here, we are battling an infestation of Giant Spider type creatures, apparently an invasion force from Castula IV. Just the other day I saw one attempting to feed off of a fully loaded dump truck traveling down the highway.
*Splat*
For a species with interstellar capabilities, they do not seem very bright.

Seriously, a piggy tail .
Denmark is really building a wall to stop German wild boar .
The boar swine pest has no vaccine , is 100% lethal, and the entire famous Danish pork industry could be wiped out overnight. I believe hunters are alerted to shoot on sight. There is belief food from retaurants is deadly as it seems the virus can be so spread. No harm to people, so far, I hope.

Now as far as those pesky polar bears raiding siberian and canadian towns – transport them to alien antarctica. There’s plenty of alien penguins just waiting for breakfast.

They will surely legislate biosecurity penalties on a case-by-case basis.

Will they now declare that winter wheat, the new yellow Rice , maize, are alien, beef cattle too? In other words that 8 billion people are living of alien food? Will all food research be declared the work of aliens?

The CO2 circus may change but the master of ceremonies is still out to cull billions.

In Florida, the Brazilian pepper crowds out all other plants except oaks. It is so invasive that when removing you must get all the roots and make sure none of the berries are left on the ground. Of course there are also pythons.

Since when has less that a third been “main”?”
=======
Very often. Check the ingredients on a bottle of jam. Berries is likely the main ingredient, followed by 10 other ingredients. If you are luckly the berries will make up 15% of the jam and the other 10 lesser ingredients will total 85%.

The main ingredient has nothing to do with percentage, it has to do with ranking.

This is a good paper in that it recognizes that man does, both purposefully and accidentally, have an effect on the distribution of competing species. Amoung fishes, the intentional introduction of carp to NA has had profound impacts on native fresh water fishes, and the inadvertent (?) introduction of the asian carp is following . The introduction of the house sparrow (English sparrow) and starling really messed with native birds. Now the zebra mussels are taking over the fresh water lakes. Leafy spurge is invading everywhere in the Canadian prairies, impacting both commercial agriculture and wild areas. Non-native trees impact forests. The list is long and the impacts vary from minor to profound. Accounting for 30% can be the “main” factor if no other single factor is that high. Epidemiologists have shown just how easy it is for modern man to move things around. Think about the questions you have to answer when going through customs.

There are 16 pages with 136 references to peer-reviewed papers etc on Extinction in the Earth Chapter of Prof. Ian Plimer’s great book: Heaven And Earth, Global Warming: The Missing Science
Quotes: “A sobering thought is that 99.99% of all species that have ever existed in planet Earth are now extinct.”
“Planet Earth has enjoyed 5 major mass extinctions.”
“Some 100 new groups of animals (phyla) appeared in the Cambrian explosion of life.”

Basalt supervolcanoes seem to be the big killer.
The Younger Dryas cooling about 12,000 years ago is the only extinction event associated with climate change, coupled with over-hunting by humans, possibly.

NOT A SPOOF:
Is humankind an alien/hominid hybrid?
By genius journalist Jim Marrs: Our Occulted History, Do The Global Elite Conceal Ancient Aliens?
Occulted is in the sense of deliberately hidden.

I thoroughly recommend both books, which are well referenced & indexed.
John Doran.

Here in sunny Australia invasive species are an enormous problem. I can list but a few
Rabbits
Foxes
Cats
Dogs
Rats
Sparrows
Cane Toad
Pigs
Horses. (Feral horses are even protected and idolised in some quarters)
Camels (These seem to be the least destructive of the lot and are actually exported to Arabia)
Goats

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